medications

If you want to go the official route, you can jump on this paper chase:

Health Permit for Import of Medications Intended for Personal Use

One copy of this approved permit must be in the package containing the meds when it arrives at the first Port of Entry. If sent via FedEx, DHL, etc., it would be the airport in CDMX.
No permit?
The package will be detained until you obtain a copy of the permit and send it to Aduanas de Mexico in CDMX.
Can't get the permit?
If you're lucky, the package will eventually be returned to the sender. If not so lucky, it will be destroyed.

I don't know where the nearest COFEPRIS office is (Lázaro Cárdenas?), but they could probably help you.

HTH...